Gross suckout

I'm playing a freeroll put on by seattlepokeropen.com. Super tight, in the top 5 or something. 30/60 blinds. I raise to 180 in EP with KT0 (tight enough that it should get some respect). Loosest player at the table (I barely cover him) calls.

FLOP:
Th 5d 7s

I bet 300, he min-raises to 600. If he hit a set, then so be it, but otherwise I'm likely ahead. I shove. Pause....call.

For your viewing pleasure:

Not so sure I put my tournament live on the line with 2 overs and a backdoor draw.

He proudly states "YES! 2nd suckout of the day" afterwards. I love players like this at the cash games! :)